Depending on the paint does depend on the cleaner used. Tamiya bottle paint I use water. Testors enamels I use varsol or turpentine. Wipe excess off on a rag, swish it in the water (for Tamiya), wipe on rag, do the same a couple more times, (don't put it in the water and leave it) don't let the bristles get to the bottom of the water pot (I use an old jar, and put the lid on - open to clean brush, so I don't touch the bottom of the jar so I don't get sediment in the bristles). Keep dipping and wiping until the brush is clean, no colour on the rag. Lay the brush flat, to keep the bristles straight. I do replace the tip guard (clear tube that came with the Vallejo "000" brush for example). If using varsol, once clean, I do rinse with water. I have several different sizes, and do use some of the Testors brushes for brushing some things, like engine blocks, etc.